The occurrence of bleeding from a cranial aneurysm results in death 68% of the time. The purpose of this study is to establish if the use of an electronic stethoscope and acoustic analysis can make bruits associated with cranial aneurysms a reliable antecedent sign, permitting a quick, inexpensive passive test that would detect an aneurysm before rupture. This system will also be used to determine the type of degree of extracranial occlusive disease by bruit detection and computer analysis.